Ladder cords designed to be used in the mounting and installation of Venetian blinds consist of two lengthwise extending, parallel crochet-chain legs, and of a plurality of transverse webs or connectors extending crosswise between the lengthwise cord legs to support the slats of the Venetian blinds. Consequently, the cross connectors must be spaced apart a distance determined by the width of the slats. When the blind is mounted in position, for example in a window frame, the upper ends of the parallel cord legs must be secured in some way to the header rail so that the blind can be mounted in position in the window frame. Furthermore, the rail equipment necessary to operate the blind, i.e. must house ladder cord roller mounted on a slat tilt drive rod.
Hitherto, the mounting and installation of the blind consisted of several steps. Initially, a few of the cross connectors of the ladder cord were removed and the cord ends thus freed were carried into the header rail, where the cord ends were clamped in some way or other to the ladder cord roller. In addition to being a rather time-comsuming operation, it was also necessary to make sure that the ends, when clamped in position, were of exactly identical lengths, as uneven lengths would result in slat misalignment in the suspended blind.